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  • Municipal Solid Waste Treatment Technologies and Carbon Finance

    World BankCarbon Finance Unit

    Thailand, BangkokJanuary 24, 2008

  • Outline

    Municipal Solid Waste (MSW) characteristics Current MSW systems in East Asia region Low cost MSW technologies Advanced MSW treatment technologies Comparison of MSW treatment technologies &

    carbon financing Recommendations

  • Waste Generation Rate

    Income Generation Rate Waste Quantity*Level kg / capita / day tons / dayLow 0.5 500Middle 0.7 700High 1.6 1,600

    * Assumed population 1.0 million.

  • Composition & Moisture Content

    Income LevelMaterial Low Middle High

    Food 40-85% 20-65% 20-50%Paper 1-10% 15-40% 15-40%Recyclables 4-25% 5-26% 11-43%Fines 15-50% 15-50% 5-20%

    Moisture 40-80% 40-60% 20-30%

    More biomass organics / moisture beneficial to LFG and composting projects not favorable for combustion and thermal technologies

    Moisture higher precipitation more rapid decomposition - - IPCC: > 1,000 mm / yr.

  • Solid Waste Composition in Bangkok

    2006 data

    Paper, 11.79%

    Plastic & Foam, 26.47%

    Stone, 0.26%

    Food Waste, 44.99%

    Glass, 1.65%

    Metal, 1.62%

    Rubber & Leather, 1.03%

    Yard Waste, 6.07%

    Bone & Shell, 0.92%

    Fabric, 5.20%

  • Solid Waste Compositionin Bangkok (cont.)

    8,000-9,000 t/d Half (44-60%) water by weight Half (49-61%) is organic1 Third (33-45%) is combustible2

    1 Food, yard and miscellaneous organic2 Paper, plastic, rubber, leather, textiles

  • Current MSWM systems in East Asia region

    MSW collection rates: Singapore (90%), Bangkok, Jakarta and Kuala Lumpur (80 85%)

    MSW practices: recycling / recovery, landfilling / open dumping, composting and incineration.

    Composting and incineration plants installed are either not working or operating at low capacities for the following reasons: High O&M costs Poor maintenance and operation of facilities Lack of expertise Poor pre-treatment (for ex. incomplete separation of non-

    compostables, inhomogeneous waste feed to incinerator) High cost of compost compared to commercial fertilizers Local opposition to incineration is growing

  • Current MSW treatment systems in East Asia region

    OthersIncinerationLandfillingOpen dumping




    Disposal / Treatment Methods (%)Country

  • Low cost MSW treatment technologies

    Low cost and sound MSW disposal / treatment methods are: Controlled landfills: has clay liner, leachate collection and

    treatment system, systematic layering and compaction of waste, regular covering, etc.)

    Sanitary landfills: has geo-synthetic liner, leachate collection and treatment system, passive venting, proper operation)

    Bio-reactor landfills: designed and operated as bio-reactor / anaerobic digestor. 15-25% less land requirement compared to sanitary landfills; maximization of LFG generation with time

    Composting (windrow or passive) In-vessel composting is not low cost technology, but well

    established and effective treatment process especially with MSW having high organic fraction (>40%), low land availability (small footprint), odor problems, problems sitingof treatment facility

  • Landfill Design

  • LFG-to-Electricity (1 MW)Durban, South Africa

  • Landfill Gas (LFG) Recovery System

  • Technology I: windrow

  • Technology II: Aerated Static Pile

  • Technology III: In-Vessel

  • Landfilling verses Low cost composting of different types of wastes (500 t/d)

    a: 65% organic content (requires sorting, composting and screening processes)b: 100% organic content (market / food waste)

    50,000 - 100,000100,000 200,000

    70,000 100,000

    O&M costUS$ / yr.

    1-1.54-5$1 M + cost of landfill

    Capital CostM US$ avoided (tons

    CO2e/ton MSW)

    600,000350,000175,000Total ERs 2009 -2014 (tCO2e)

    Market/foodbMSW aSanitary Landfill

  • Advanced MSW treatment technologies (AMSWTT)

    AMSWTT also referred to as waste to energy (WTE) technologies require 5 components:

    1. Front end MSW pre-processing: is used to prepare MSW for treatment by the AMSWTT and separate any recyclables

    2. Conversion unit (reactor)3. Gas and residue treatment plant (optional)4. Energy recovery plant (optional): Energy / chemicals

    production system includes gas turbine, boiler, internal combustion engines for power production. Alternatively, ethanol or other organic chemicals can be produced

    5. Emissions clean up

  • Pyrolysis Non-commercial has been proven technically at pilot

    scale but not commercial scale / financially Thermal degradation of organic materials through use of

    indirect, external source of heat Temperatures between 300 to 850oC are maintained for

    several seconds in the absence of oxygen. Product is char, oil and syngas composed primarily of O2,

    CO, CO2, CH4 and complex hydrocarbons. Syngas can be utilized for energy production or

    proportions can be condensed to produce oils and waxes Syngas typically has net calorific value (NCV) of 10 to

    20 MJ/Nm

  • Gasification Non-commercial has been proven technically (pilot scale) but

    not not commercial scale / financially Can be seen as between pyrolysis and combustion

    (incineration) as it involves partial oxidation. Exothermic process (some heat is required to initialize and

    sustain the gasification process). Oxygen is added but at low amounts not sufficient for full

    oxidation and full combustion. Temperatures are above 650oC Main product is syngas, typically has NCV of 4 to 10

    MJ/Nm3 Other product is solid residue of non-combustible materials

    (ash) which contains low level of carbonN t N t l h NCV f d 38 MJ/N 3

  • Plasma Gasification Non-commercial has been proven technically (pilot scale) but

    not not commercial scale / financially Use of electricity passed through graphite or carbon

    electrodes, with steam and/or oxygen / air injection to produce electrically conducting gas (plasma)

    Temperatures are above 3000oC Organic materials are converted to syngas composed of

    H2, CO Inorganic materials are converted to solid slag Syngas can be utilized for energy production or

    proportions can be condensed to produce oils and waxes

  • Plasma gasification

    Plasma Plasma ReactorReactor

    Heat RecoveryHeat RecoveryGas CleaningGas Cleaning

    Boiler(Steam Generator) Turbo-generator

    Medium Pressure Steam

    High Pressure Steam



    Sync Gas

    Clean Sync Gas

    CO2 emissions Oxygen



    Gasification by Gasification by PlasmaPlasma

  • Incineration

    Combustion of raw MSW, moisture less than 50% Sufficient amount of oxygen is required to fully oxidize

    the fuel Combustion temperatures are in excess of 850oC Waste is converted into CO2 and water concern about

    toxics (dioxin, furans) Any non-combustible materials (inorganic such as

    metals, glass) remain as a solid, known as bottom ash (used as feedstock in cement and brick manufacturing)

    Fly ash APC (air pollution control residue) particulates, etc

    Needs high calorific value waste to keep combustion process going, otherwise requires high energy for maintaining high temperatures

  • Anaerobic digestion

    Well known technology for domestic sewage and organic wastes treatment, but not for MSW

    Biological conversion of biodegradable organic materials in the absence of oxygen at temperatures 55 to 75oC (thermophilic digestion most effective temperature range)

    Residue is stabilized organic matter that can be used as soil amendment after proper dewatering

    Digestion is used primarily to reduce quantity of sludge for disposal / reuse

    Methane gas generated used for electricity / energy generation or flared

  • Advanced MSW treatment technologies (cont.)

    General characteristics of AMSWTT are: Well established technologies in industrial sector /

    domestic sewage (for anaerobic digestion), but not in the MSW sector. Exceptional case is incineration

    For MSW, the AMSWTT are at demonstration stage, have not been designed for large MSW volumes (largest installed capacity is 400 t/d pyrolysis plant in Japan)

    Very high capital, and O&M costs Require skilled engineers / operators Have not been designed to handle heterogeneous mixed

    MSW Not optimized in terms of overall energy and materials


  • Comparison of AMSWTT

    9 1510 205 - 10500Sanitary landfill

    12 - 3080 - 15016 - 9070-270Pyrolysis





    Plant capacity


    12 1815 - 3010 15Bioreactor landfill

    9 1530 - 6050 80In vessel composting

    12 - 2460 - 10020 - 80Anaerobic digestion

    12 3080 - 15050 - 80Plasma gasification

    54 9680 - 12030 - 180Incineration12 3080 - 15015 - 170Gasification

    Planning to commissioning


    O&M cost(US$/ton)

    Capital cost(M US$)


  • Recommendations

    Carry out detailed feasibility study using Municipal Solid WasteDecision Support Tool (MSW DST) or similar model for a city, forevaluation of technical, economical, environmental, siting / permitting and social aspects to come up with most efficient integrated MSW system

    AMSWTT should not be considered at this s


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